Pawn stars airs Thursday nights on history channel. And next, elle Macpherson, she is looking good. She blew up Twitter with a smoking hot photo that she posted of herself looking unbelievable in a bikini at age 50. She's revealing the diet and beauty secrets she swears by to keep looking so fit and fabulous. Sara Haines has the details. Reporter: Known as the body, she was in the late 80s, gracing "Sports illustrated" a record of five times. And just over the weekend, the blond bomb shell tweeted out this photo of her rocking bikini bod. Can you believe she just celebrated the big 5-0? I feel more beautiful than ever. Reporter: What are the secrets that you news to look as gorgeous as you look today? When you laugh, it changes everything. It changes the spirit and how people perceive you. An alkaline diet. I swear by it. Mostly vegetables, a little bit of fish, no coffee, no alcohol. Reporter: She swears by exfoliating every day, and at least eight hours of sleep. One of the biggest beauty tips, and it's cliche, I drink three liters of water today. Reporter: She doesn't go to the gym. I have always done a lot of sport, I'm Australian. It's running, hiking, road biking. Not just looking thin, but enjoy what you're doing. Reporter: That's my favorite one. This is my favorite bra. Reporter: Added to her legacy, she launched a new line called the body. Women choose lingerie because they feel sexy, and feeling comfortable in your body. Reporter: Now after 30 years in front of the camera, she says her favorite gig -- Working with friends. Oh, my god. Sorry about that, my thongs are too delicate for the drier. That was such a blast. I feel just really blessed that I've had a diverse and interesting career. Reporter: For "Good morning America," Sarah Haines, ABC news, New York. We were discussing the new line -- I had a real checkout moment there. We were talking about lingerie. I didn't know she had that line. No, not going to listen. Amy and I are like, it's fabulous. Check out this style, it's the best. You see, she does have a lingerie line. And we can all agree -- Looks great. Her mom and her dad, those are good genes. And drinking her product, it's called the super elixir.

This transcript has been automatically generated and may not be 100% accurate.

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